how to solve the problem of "cannot borrow articulation as mutable more than once at a time" when I use the feature of artilucation.creaet_link(...)

[YesanQin]

Excuse me, how should I to resolve this problem?
when I use the method 'articulation.create_link()' to create a link, because of the result of this method will as a parameter in next called of 'articulation.create_link()',that cause the lifetime of first value as same as the second called, so occur Multiple variable borrowings。
I try to clone reference and 'root_link_met()' ,but still can not resolve this problem.

[YesanQin]

I'm not sure that the response type(which signature Option<&mut Self::ArticulationLink>) of the method which signature 'articulation.create_link(...)' should be 'Option<OwnerSelf::ArticulationLink>',and I tried is ok~